In recent years, compact projectors that can be easily carried about and can display images on large screens have been actively developed. Compact projectors that can be connected to notebook PCs and the like and video cameras and the like having built-in projectors that can project recorded images are already available in the market. Thus, it is predicted that projectors built in cellular phones or smart phones will also become available in future.
As a projector, a scanning-type image display device that couples and scans beams from a plurality of laser beam sources is known. It is also predicted that such a projector will be mounted on a vehicle or the like utilizing the high luminance of an image, and be applied to a head-up display so that an image is projected onto a windshield or a navigation image is displayed, for example. In such a scanning-type image display device, the projection image quality may deteriorate due to expansion or contraction of components caused by a temperature change. In addition, there is a need to set the temperature of each component to a heatproof temperature or lower.
As a heat-insulating structure for an optical module, for example, a structure disclosed in PTL 1 is known. In PTL 1, peripheral parts of the optical module housed in a package are covered with a heat-insulating material. Further, PTL 2 discloses that a cover is provided so as to prevent transfer of heat generated from a polygon mirror.